An isolation risk assessment of medical service facilities under flood scenarios in China's coastal areas

Medical service facilities (MSFs) are critical elements at risk during flood scenarios under a changing climate. Beyond direct inundation, MSFs also face indirect risks from road network disruption and isolation risks from complete access loss, which are often overlooked. To address this research gap, this study develops an isolation index to quantify the direct, indirect, and isolation risks of MSFs. A case study in China's coastal areas reveals that indirect risk (affecting 11.60% of MSFs) significantly outweighs direct risk (2.58%) under a current 100-year flood, with 9.02% facing total isolation risk – 3.50 times the direct risk. Under the future Representative Concentration Pathway 8.5 (RCP8.5) scenario, indirect and isolation risks are projected to escalate, with risk propagation from no risk to indirect, isolation, and direct risks. By 2100, 13.00% of currently unaffected facilities may encounter indirect risk, while 70.54% of MSFs currently under indirect risk (excluding isolation risk) and 29.59% of those under isolation risk may eventually face direct inundation. These findings highlight the growing severity of indirect and isolation risks relative to direct risks in impacts. The study provides empirical evidence for policymakers to enhance MSFs' resilience through identifying and managing multiple risks.